As described in, for example, a patent document 1, a drive system of an electrically driven dump truck includes: a prime mover; an electronic governor for controlling the revolution speed and torque of the prime mover; an alternating-current generator driven by the prime mover; two electric motors, each of which is driven by the electric power supplied by the alternating-current generator, the two electric motors driving, for example, right and left rear wheels; two inverters, each of which is connected to the alternating-current generator, and each of which controls each of the electric motors (for example, induction motors); and a control unit for calculating the target revolution speed corresponding to the operation amount of an accelerator pedal to control the electronic governor, and for calculating torque instruction values of the two electric motors in response to the operation amount of the accelerator pedal to control the two inverters on the basis of the torque instruction values so that each of the electric motors is controlled.    Patent document 1: JP-A-2001-107762